1. Field of the Invention
The present invention relates to an adapter feeding apparatus for sequentially feeding adapters in assembling plug joints connected to an engine direct-coupled coil of an ignition coil system for an internal combustion engine of an automotive vehicle for electrical connection to a spark plug.
2. Description of the Background Art
Conventionally, this type of plug joint includes a tubular adapter 1 made of PBT (polybutylene terephthalate) and the like, as illustrated in FIGS. 6 and 7. The adapter 1 comprises an adapter body 1a, a bushing mounting portion 1b formed on a first end of the adapter body 1a and to which is mounted a bushing element 2 made of silicone rubber and the like for connection to a spark plug, and a cap mounting portion 1c formed on a second end of the adapter body 1a and to which is mounted a cap element 3 made of silicone rubber and the like for connection to an ignition coil and for contact with an outer peripheral surface of a periphery of a plug hole in a cylinder head.
The bushing element 2 is bonded to the bushing mounting portion 1b of the adapter 1 with an adhesive, and the cap element 3 is bonded to the cap mounting portion 1c with an adhesive for assembly of a plug joint 5.
However, the plug joint 5 has been assembled in such a manner that an operator manually supplies the adapter 1 in a predetermined position to an adapter holding and rotating mechanism for holding and rotating the adapter 1, applies an adhesive, for example, to an outer peripheral surface of the bushing mounting portion 1b of the adapter 1 being rotated by the adapter holding and rotating mechanism by using a brush, and then mounting the bushing element 2 on the bushing mounting portion 1 to bond the bushing element 2 to the bushing mounting portion 1b.
Likewise, the operator applies the adhesive to the cap mounting portion 1c and then mounts the cap element 3 on the cap mounting portion 1c to bond the cap element 3 to the cap mounting portion 1c.
Thus, the operator manually supplies the adapters 1 to the adapter holding and rotating mechanism, resulting in variations in adapter feeding paces.
Additionally, the feed of the adapters 1 depends upon operator's skill. A resemblance in configuration between the bushing mounting portion 1b and cap mounting portion 1c of the adapter 1 might cause the operator to make the mistake of feeding the adapter 1 in an improper orientation due to operator fatigue, resulting in low reliability.